The American and French ambassadors to Damascus now have some company as occasional human shields for the Syrian protest movement. At the vigil on Tuesday of Giyath Matar, a human rights activist tortured and killed in custody, Robert Ford and Eric Chevallier were joined by other western envoys, including the UK's Simon Collis, and representatives from Germany, Canada, Japan, Netherlands and the EU.

British diplomats said that if Collis had been in the country at the time he would have joined Ford and Chevalier on their celebrated trips to Hama in July, which drew attention to the threat of a bloodbath in the opposition stronghold. Ford's high-profile role in particular led to violent pro-government protests outside the US embassy and a ban on diplomats travelling without specific permission.

The measure of protection provided by the coordinated diplomatic presence is limited. The Washington Post's Liz Sly tweeted that the funeral tent at the Matar wake was trashed by security forces an hour later. And the risk to the diplomats is real. It is an uncomfortable and somewhat bizarre position to be in being the diplomatic representative of a country openly calling for the toppling of the host regime. Ford has noted on his Facebook page that he has received death threats, but British diplomats say there will be more such public appearances at opposition events.

"We have said we will stand with the Syrian people, whether that means grieving with them or talking to the opposition," a diplomat said. He added that it was critical that the Syrian protesters should not feel forgotten by the world while the focus is on Libya and the Palestinian resolution next week at the UN.

Such public demonstrations of solidarity are among a very limited set of tools the West has in Syria. Any punitive UN Security Council resolution is being held up by China and Russia, in part as pay-back for resolution 1973 in March, through which both countries feel they were misled into giving an unwitting green light to regime change in Libya. David Cameron's trip to Moscow and Alain Juppé's recent mission to Beijing failed to bring any movement on a Syrian resolution, diplomats in London concede.

Going too far down the sanctions route could easily turn out to be counter-productive in any case, the International Crisis Group's Peter Harling argued recently. In an article entitled 'How not to prolong the Syrian agony' Harling urged western capitals to resist the urge to doing anything just to be seen to be doing something, adding: "the overriding principle should remain to do no harm".